In the MMT core, focused laser beams are used to achieve high-resolution imaging and to perform precisely controlled micro-manipulations of biological tissues in situ and in vivo. This core includes confocal and nonlinear optical microscopy technologies, optical tweezers and advanced micro-beam techniques. During previous LAMMP funding cycles, the MMT core has made many pivotal contributions to the field of laser-based microscopy, and has broken new ground in applying these technologies to relevant biomedical problems. In the current LAMMP renewal, we continue to push laser microscopy techniques for addressing pertinent questions in cell and tissue biology.